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We studied the optical properties of hybrid multilayer microspheres (HMMs). We prepared multilayer particles with alternating radial layers of gold nanoparticles (NPs) and poly(methyl methacrylate) and achieved control over particle size, the thickness of particle layers, and the surface coverage of gold NPs. We showed the ability to tune the spectral characteristics of the HMMs, which was based on frequency dispersion of the dielectric constant of polymer-metal NP structures. Good agreement between experimental and theoretical extinction properties of the HMMs was obtained. In comparison with multilayer structures synthesized solely from polymers, hybrid multilayer microspheres have a larger refractive layer contrast between adjacent layers, which is important for practical applications in optoelectronic devices. Key words: hybrid polymer-inorganic materials, polymer microspheres, gold nanoparticles, optical properties, extinction spectra. On a etudie les proprietes optiques de microspheres multicouches hybrides (MMH). On a prepare les particules a multicouches comportant des couches radiales alternantes de nanoparticules (NP) d'or et de poly(methacrylate de methyle) et on a pu controler la taille des particules des couches et la surface de la couverture des nanoparticules d'or. On a pu controler les caracteristiques spectrales des microspheres multicouches hybrides en ajustant la frequence de dispersion de la constante de dielectrique des structures des nanoparticules polymere-metal. On a obtenu un bon accord entre les proprietes d'extinction experiinentales et theoriques des microspheres multicouches hybrides. Par comparaison avec les structures multicouches synthetisees uniquement a partir de polymeres, les microspheres multicouches hybrides possedent un plus grand contraste de refraction par couche entre les couches, propriete importante pour les applications pratiques dans les appareils optoelectroniques. Mots-cles : materiaux hybrides polymere-inorganique, microspheres de polymere, nanoparticules d'or, proprietes optiques, spectres d'extinction. [Traduit par la Redaction] doi: 10.1139/V09-172, Introduction Polymer microspheres with a multilayer onion-like structure possess optical properties that are useful in photonic crystals, (1-2) optical data storage, (3-4) biometrics, (5,6) and, sensing and single-particle optical limiting. [...]

A process for the gram scale synthesis of the oxygen bridged dimer of boron subphthalocyanine, μ-oxo-(BsubPc)2, has been developed. During the development it was found that a wide range of reaction pathways under diverse conditions lead to μ-oxo-(BsubPc)2 formation. However, obtaining μ-oxo-(BsubPc)2 as the main reaction product in appreciable yields and its subsequent isolation were extremely challenging. The best balance of purity, yield and conversion was achieved with a time controlled reaction of an equimolar reaction of HO-BsubPc with Br-BsubPc in the presence of K3PO4. The purification involved sequentially Soxhlet extraction, Kauffman column chromatography and train sublimation. We have repeated the process and yields ranged from 27 to 30% of pure, doubly-sublimed μ-oxo-(BsubPc)2. This process also enabled the synthesis of unsymmetric μ-oxo-(BsubPc)2s by reaction of HO-BsubPc with Br-F12BsubPc, Cl-Cl6BsubPc and Cl-Cl12BsubPc. After synthesis the solution-state properties of the unsymmetric μ-oxo-(BsubPc)2s were investigated, and compared to the symmetric μ-oxo-(BsubPc)2 and more broadly to other BsubPcs. The electronic properties of μ-oxo-(BsubPc)2 were found to differ from its unsymmetric counterparts, but were found to be similar to halo-BsubPcs. Furthermore, the photophysical properties of μ-oxo-(BsubPc)2, both symmetric and unsymmetric, differed greatly from all other known BsubPcs. [ABSTRACT FROM AUTHOR]

The ability to control the solid-statestructure of organic electronicmaterials can have a large effect on the quality of the devices towhich they are applied. In this paper, we describe the use of π–πinteractions to direct the crystal structure/solid-state arrangementof boron subphthalocyanine (BsubPc) derivatives by taking advantageof the π-electron-deficiency (π-acidity) of the BsubPcmolecular fragment. First, we outline why BsubPc is a π-acidby looking at its chemical characteristics and the structure of crystalsformed with other π-acidic moieties. Then we show how the solid-statearrangement of BsubPc can be purposefully altered by adding π-basicsubstituents. We found that adding a naphthoxy substituent providesan interaction that is strong enough to direct BsubPc into a novelsolid-state arrangement made up of ribbons (or catemers) of moleculeslinked through π-stacking interactions between the naphthoxyand neighboring BsubPc molecular fragments. A similar effect was alsoseen when the naphthoxy fragment was added to the stronger π-acidperfluoro-BsubPc (F12BsubPc). [ABSTRACT FROM AUTHOR]

The crystal structures of three sulfonate pseudohalide derivatives of boron subphthalocyanine (BsubPc) are described and compared with four structures of three published sulfonate derivatives. Benzenesulfonate boron subphthalocyanine [(benzenesulfonato)(subphthalocyaninato)boron, C30H17BN6O3S, (I)] crystallizes in the space group P with Z = 2. The structure contains two centrosymmetric π-stacking interactions between the concave faces of the isoindoline units in the BsubPc ligands. 3-Nitrobenzenesulfonate boron subphthalocyanine [(3-nitrobenzenesulfonato)(subphthalocyaninato)boron, C30H16BN7O5S, (II)] crystallizes in the space group P21/ c with Z = 4. The structure contains an intermolecular S-O...π interaction from the sulfonate group to a five-membered N-containing ring of an isoindoline unit on the concave side of a neighbouring BsubPc ligand, at a distance of 3.151 (3) Å. The crystal of methanesulfonate boron subphthalocyanine [(methanesulfonato)(subphthalocyaninato)boron, C25H15BN6O3S, (III)] was produced via sublimation and it is not a solvate, in contrast with two previously published structures of the same compound. Compound (III) crystallizes in the space group P21/ n with Z = 2, and its structure is similar to that of the more common compound Cl-BsubPc. [ABSTRACT FROM AUTHOR]

Boronsubphthalocyanine (BsubPc) derivativesare materialsthat have recently seen an increase in attention, particularily forapplication as colorants and functional materials in organic electronicdevices. However, the solubilities of most BsubPcderivativesare too low to utilize solution-based processing techniques. Wherethere are derivatives that are soluble, they rely on the additionof large alkyl chains for solubilization the result of which is anincrease in the molecular weight and a decrease of the specific absorptivityof the BsubPc. In this paper we disclose the identityof two mass-efficient, highly soluble BsubPcderivatives:3-methylphenoxy-BsubPcand 3,4-dimethylphenoxy-BsubPc. We compare their solubilities and crystal packingstructures to previously known BsubPcderivatives. Weput forward a symmetry-based argument for the reason for their surprisinglyhigh solubility wherein we treat the molecules as two separate fragments:the phenoxy group and the BsubPcgroup. The symmetry-basedargument suggests that by ignoring the BsubPcfragmentcommon to each derivative a better estimate of the relative solubilitiescan be estimated through previously established empirical formulas. [ABSTRACT FROM AUTHOR]

The synthesis and study of a series of pseudohalides of boron subphthalocyanine (BsubPc) are reported. Each pseudohalide has been compared to the more common chloride and bromide of BsubPc, and we have found that most react slower under standard phenoxylation and hydrolysis conditions. Three pseudohalides (TsO-BsubPc, MsO-BsubPc, and BsO-BsubPc) do not hydrolyze at all even after prolonged periods of time in the presence of water. Single crystals of TsO-, MsO-, and ClsO-BsubPc were obtained, and their structures were unambiguously determined. [ABSTRACT FROM AUTHOR]

We report the synthesis and characterization of a series of para-halo-phenoxy-boronsubphthalocyanines (BsubPcs). Across this series, a crystal polymorph of p-bromophenoxy-BsubPc (α-BrPhO-BsubPc) contains a clear and discernible π–Br interaction directing crystallization into a motif not previously seen for phenoxy-BsubPcs. [ABSTRACT FROM AUTHOR]

We report the synthesis and systematic description of a series of five para-substituted phenoxy-BsubPcsincluding their characterization in the crystal state. The nature of the substituents on the phenoxy molecular fragment was chosen so as to vary both the size and electronegativity: specifically with increasingly bulky para-alkyl groups from hydrogen to tert-octyl and a single electronegative substitute (F). Examination of the arrangement of the phenoxy-BsubPcswithin single crystals allows us to place each into one of the two categories. The first, which contains all but one of the derivatives, has a repeating motif which is made up of dimers of the BsubPcmolecular fragments. The second, containing only the derivative possessing the large tert-octyl substituent, is characterized by the formation of ribbons instead of dimers of the BsubPcfragment. Regardless of motif the arrangement of the BsubPcmolecular fragments was found to be convace–concave. [ABSTRACT FROM AUTHOR]

This letter reports optical properties of spherical dielectric particles with alternating layers of high and low refractive indices. The authors “predesigned” and synthesized polymer microspheres with alternating polystyrene and poly(trifluoroethyl methacrylate) layers of various thicknesses. Extinction of the microspheres was examined in a broad spectral range. A multipole expansion of electromagnetic field was applied for calculating the extinction efficiency of the particles. Excellent agreement was obtained between experimental and theoretical extinction curves. [ABSTRACT FROM AUTHOR]

A process for the gram scale synthesis of the oxygen bridged dimer of boron subphthalocyanine, μ-oxo-(BsubPc)2, has been developed. During the development it was found that a wide range of reaction pathways under diverse conditions lead to μ-oxo-(BsubPc)2 formation. However, obtaining μ-oxo-(BsubPc)2 as the main reaction product in appreciable yields and its subsequent isolation were extremely challenging. The best balance of purity, yield and conversion was achieved with a time controlled reaction of an equimolar reaction of HO-BsubPc with Br-BsubPc in the presence of K3PO4. The purification involved sequentially Soxhlet extraction, Kauffman column chromatography and train sublimation. We have repeated the process and yields ranged from 27 to 30% of pure, doubly-sublimed μ-oxo-(BsubPc)2. This process also enabled the synthesis of unsymmetric μ-oxo-(BsubPc)2s by reaction of HO-BsubPc with Br-F12BsubPc, Cl-Cl6BsubPc and Cl-Cl12BsubPc. After synthesis the solution-state properties of the unsymmetric μ-oxo-(BsubPc)2s were investigated, and compared to the symmetric μ-oxo-(BsubPc)2 and more broadly to other BsubPcs. The electronic properties of μ-oxo-(BsubPc)2 were found to differ from its unsymmetric counterparts, but were found to be similar to halo-BsubPcs. Furthermore, the photophysical properties of μ-oxo-(BsubPc)2, both symmetric and unsymmetric, differed greatly from all other known BsubPcs.

With the knowledge that the dominant photodynamic therapy (PDT) mechanism of 1a (WST09) switched from type 2 to type 1 for 1b (WST11) upon taurine-driven E-ring opening, we hypothesized that taurine-driven E-ring opening of bacteriochlorophyll derivatives and net-charge variations would modulate reactive oxygen species (ROS) photogeneration. Eight bacteriochlorophyll a derivatives were synthesized with varying charges that either contained the E ring (2a-5a) or were synthesized by taurine-driven E-ring opening (2b-5b). Time-dependent density functional theory (TDDFT) modeling showed that all derivatives would be type 2 PDT-active, and ROS-activated fluorescent probes were used to investigate the photogeneration of a combination of type 1 and type 2 PDT ROS in organic- and aqueous-based solutions. These investigations validated our predictive modeling calculations and showed that taurine-driven E-ring opening and increasing negative charge generally enhanced ROS photogeneration in aqueous solutions. We propose that these structure-activity relationships may provide simple strategies for designing bacteriochlorins that efficiently generate ROS upon photoirradiation.

The crystal structure of the title compound, C(31)H(16)BN(7)O, (CNPhO-BsubPc) is characterized by pairs of π-π stacking inter-actions between the concave faces of inversion-related BsubPc fragments with a centroid-centroid distance of 3.600 (1) Å. In addition, these pairs of mol-ecules are linked into chains along [101] through further weak π-π stacking inter-actions with a centroid-centroid distance of 3.8587 (9) Å. There are also weak C-H⋯π(arene) inter-actions within the chains.

The main feature of the structure of the title compound, C(30)H(16)BN(7)O(3) or NO(2)PhO-BsubPc, are pairs of mol-ecules linked through π-inter-actions between the concave faces of the BsubPc fragments at a distance of 3.5430 (11) Å across an inversion centre. However, the angle between the planes of the five- and six-menbered rings involved in this inter-action is 1.44 (10)°, causing the inter-acting BsubPcs units to be slightly askew rather than parallel as is typical for π-stacking inter-actions.

In the title compound, C(32)H(19)BN(6)O(2), the B atom adopts a BON(3) tetra-hedral coordination geometry. In the crystal, pairs of mol-ecules are associated through aromatic π-π stacking inter-actions between the concave faces of the boronsubphthalocyanine fragments at a centroid-centroid distance of 3.4951 (19) Å and a weaker inter-action of the same type between the convex faces of the same group [centroid-centroid separation = 3.5669 (18) Å] also occurs.

In the title compound, C(31)H(7)BF(12)N(6)O, mol-ecules are arranged into one-dimensional columns with an inter-molecular B⋯B distance of 5.3176 (8) Å. Bowl-shaped mol-ecules are arranged within the columns in a concave bowl-to-ligand arrangement separated by a ring centroid distance of 3.532 (2) Å between the benzene ring of the 4-methyl-phen-oxy ligand and one of the three five-membered rings of a symmetry-related mol-ecule.

Nine derivatives of chloro boron subphthalocyanine (Cl-BsubPc, 1) have been synthesized and characterized. Seven dimers of Cl-BsubPc have been synthesized by reaction with biphenol (2a), bisphenol A (2b), bisphenol F (2c), bisphenol O (2d), bisphenol P (2e), bisphenol S (2f) and bisphenol Z (2g). For comparison two monomeric phenoxy- (3a) and 4-methylphenoxy (3b) BsubPcs have also been synthesized. Crystals were grown for dimer 2c, whereas all attempts to grow crystals of the remaining dimers resulted in the formation of molecular glasses or amorphous precipitates. Analysis on the structure of 2c suggests that the rigidity and aromatic nature of the central bisphenolic directs the crystal packing. The solubility of the BsubPc dimers in a variety of common organic solvents was measured and compared to that of Cl-BsubPc (2) and monomers 3a and 3b. We have defined ranges for classifying BsubPc derivatives based on their solubility in these solvents: pigment < or = 1 x 10(-8) M, 1 x 10(-3) M < or = pigment-like > 1 x 10(-8) M, 1 x 10(-2) M < or = dye-like > 1 x 10(-3) M, and dye > 1 x 10(-2) M. From this Cl-BsubPc (1) and compounds 2a, 2b, 2c, 2e and 2g are pigment-like while compounds 2d, 2f, 3a and 3b are dye-like. None are exclusively pigments or dyes. In this first approximation of this dye versus pigment classification we have not considered other processes besides solvation which could be undesirable such as polymorphic changes or Ostwald ripening. We have concluded that derivatization of Cl-BsubPc (1) with bisphenols and phenols can be used to control the solubility of BsubPc derivatives. We have also concluded that Cl-BsubPc (1) should not be considered a dye rather is pigment-like in its solubility.